Airplane towing mechanism



E. L. NOTESTEIN ET AL June 8, l948 AIRPLANE TOWING MECHANISM 2Sheets-Sheet 1 Filed Jan. 15, 1945 June 3, 1948- E. L. NOTESTEIN ETAL2,443,114

AIRPLANE TOWING MECHANISM 2 Sheets-Sheet 2 Filed Jan. 15, 1945 Jizz/erzdiam:

Patented June 8, 1948 UNITED STATES "PATENT OFFICE 2,443,114 AIRPLANErowm'e MECHANISM Edison L. Notestein,

Wayne,

and Robert J.

Rumpf, Dearborn, Mich, assignors to Consolidated Vultee AircraftCorporation, San Diego, Calif., a corporation of Delaware ApplicationJanuary 15, 1945, Serial No. 572,840

8 Claims. 244-3) over, previously designed mechanism for the samepurpose and is characterized by high efiiciency and the fact that it maybe released at will by the pilot of the airplane being towed.

Another object of the invention is to provide an airplane towingmechanism which comprises a tow cable having at its front end anysuitable means for attachment to the tow airplane and at its rear end aswivel variety connecting member, and also comprises a split collar therear end of which embodies means for detachably connecting it to thepropeller hub nut of the airplane being towed and the front end of whichis provided with the socket for the swivel variety connecting member onthe rear end of the tow cable.

Another object of the invention is to provide a towing mechanism of thelast mentioned'type and character in. which the split collar consists ofa pair of semi-circular sections certain opposed ends of which arepivotally connected together and the distal ends of which haveassociated therewith a latch device for releasably securing themtogether.

Another object of the invention is to provide an airplane towingmechanism of the type and character under consideration in which thesocket at the front end of the split collar and the swivel varietyconnecting member on the rear end of the tow cable are so shaped anddesigned that when the latch device between the distal ends of thecollar sections is released the swivel variety connecting memberoperates to spread apart the collar sections into an open. positionwherein they are released from the propeller hub nut of the airplanebeing towed.

Another object of the invention is to provide an airplane towing deviceof the last mentioned character in which the means for detachablyconnecting the rear end of the split collar to the propeller hub nut ofthe airplane being towed is in the form of a pair of lugs which areconnected to and project inwards from the central portions of the collarsections, are adapted to fit within and interlock with the usual wrenchholes in the propeller hub nut and are so designed and arranged thatthey beccme disengaged from the wrench holes in response to spreadingapart of the collar sections.

A further object of the invention is to provide an airplane towingmechanism of the aforementioned character in which the collar isconnected by a flexible element to the swivel variety connecting memberin order that upon release of the latch device it is pulled away fromthe propeller hub nut of the airplane being towed, and the latch devicefor releasably securing the collar sections together comprises a levertype plate which is manipulable by the pilot of the airplane being'towed through the medium of a release cable.

A still further object of the invention is to provide an airplane towingmechanism which effectively and efliciently fulfills its intendedpurpose, consists of but a comparatively small number of parts and maybe produced at a low cost.

Other objects of the invention and the various advantages andcharacteristics of the present airplane towing mechanism will beapparent from a consideration of the following detailed description.

The invention consists in the several novel features which arehereinafter set forth and are more particularly defined by the claims ofthe conclusion hereof.

In the drawings which accompany and forma part of this specification ordisclosure and in which like letters and numerals of referencedenote'like or corresponding parts through the several views:

Figure 1 is 'a side elevation showing a tow airplane and an airplane tobe towed connected together by a towing mechanism embodying theinvention;

Figure 2 is a fragmentary perspective showing the mechanism in itsoperative position wherein the split collar is in connected relationwith the propeller hub nut of the towed airplane;

Figure 3 is a similar perspective showing the latch device, the collarand the swivel variety connectingmember in their released positions;

Figure 4 is an enlarged vertical longitudinal section of the mechanism;and

Figure 5 is a transverse section on the line 5--5 of Figure 4.

The towing mechanism which is shown in the drawings constitutes thepreferred form or embodiment of the invention. It is illustrated inconnection with a tow airplane A and an airplane B to be towed andserves as a medium or instru- 3 mentality for releasably connecting thetwo airplanes together during flight. The airplane B is illustrated inthe drawings as being of the conventional single engine tractor type andcomprises a wing equipped. fuselage I) having an enclosed pilotscompartment bl: in the front-.centra'l portion thereof. 'I hefront.=:enol of the fuselage b houses the propeller driving engine (notshown) and the latter embodies a crank shaft the front: L end of whichprojects through the.huh..o.the..l0-.

*define-a'rearwardly flared socket for the swivel ivarietycconnecting,smember I when the collarxeecctionsyarerinztheiraclosed or operative position.

propeller and is provided with a tubulannuth The nut, as wellunderstoodin the-art, serizesto lock the propeller hub to the-enginecrank; haft and is located in front of theipropellehhub: It... iscylindrical so far as contour is concerned aiideu embodies in the sideportions \ofnits frontsend apair oi diametrically opposite wrenchholesThe towing mechanism comprises as its.-.-prin-. 2

cipal components or parts. a tow cable 6, a swivel typeconnecting-member]; asplit-collar 8 and a,-

has any'suitablei means (notrs-hownl-at itsfront end for attachment tothe rear:endpof:theifuselage 1of1the: tow airplane A. i' The swivel;typeconnectinglmember' I isclocated :at :the arear endof the. tow:ca'bleiiiand isconnected tortherlattertby an zeye'bolt :'l 0; :Assbest 2shown-in Figure 4- of'rthe drawings; the-amember 1-issrearwardly-fiaredas a-.res'ult= o'frther fact that itiishemispherical: solar? assshapie 101:: contour iSijCOIlGETHGdJ; Theeyebolt i i! a is: of .--conventional Ldesigrrrand "oonsists of. a nutequippedshank lhand an eye .12; Fllhe-shank I I extends. throughanvaxiallyz positioned bore .1 3 in the swivel .varietyconnecting; member,:1 and -i has the eye cmconnectedto its 'front :end. The nut is: mountedOn the rear end of the shanleof theueyebolt, abutseagainstxtheifiatmiace; of the member :1 and coacts=with:.the-eye H tohold the eyebolt against-..:=longitudinal1-axial adisplacement.

relatively to :the member LI. When "the towing mechanism is :in .use"theacurved :orrrouncled surface 'Ufithe: member I .afacesrforwards. Therear end fof thel cable 6 isprov'ided with arloop which extends throughthe eye l2 of the eyebolt.

- Thesplit collarv 8 serves releasablyto connect the-swivel varietyrconnectingmem'ber l 1 to :the propeller hub nut- 1) and" consists;.ofa. pairs :of complemental oppositely positioned"semi-circular-sections?! It is.-conteinplated.that when the mechanismiskinau-sei orsoperaticn the :engine ifor propellingithe' airplane .Bwill beat; resta'ndlthe propeller will; be: locked?againstsoecallediwindmilling. The semi-circular sections Mu oft the collar 81are;normally..positioned in: horizontal a1ignment \and;.:have a :pivotalconnection-jibetween-their lower endszirn .orderi'thattheyare capable ofbeing swung to and from one another into 1 and: out :of theirnormalzzoperating. position.

Theipivotal connection betweenthe lower. ends :of i

the collar sections r comprises .a' rectilinear series of lugs |5uon thelower endsrofxzsaidrcollar:sectiODSI'LaIId iII; addition a. pivot:.pin-.l6. L'Thelugs l 5 varenpref-erably.formed .asiintegrat'parts 'ofthe collar sections. They; proiectinwardsiand :down- 4 adapted when thecollar is in operative relation with the propeller hub nut 12 to fitwithin and interlock with the wrench holes b in the nut. When the collarsections M are spread or swung apart the lugs l8 become disengaged fromthe WIGIIGhv-hOlGs b thus disconnecting thepcollar fromithenut.:Thefrontends of the collar sections it are provided with integralinwardly ex- 5. ;-..tcn;ding arcuate flanges I9 the inner surfaces ofhich. are concave in cross section and together When: theumember' 1.- isin connected relation with Ethel-collar flowhilelthe collar sections areclosed the curved or rounded surface of the member fits 'against'theconcave surfaces of' the flanges l9 andrjt'he member is free to swivelwithin the 7 socket which is formed by the flanges [9 of the collarsections. Whenthe upper ends ofthecollarsectionsare. released ashereinafterdescribed forward tension .on theswivel variety connectingmember. 'lresults in thesmember cammingnor forcing-the collarsectionsinto their. open. positionswhereinthe. lugs [8 are.disengagedfrom the-wrench holes b3 in the. .propellerhuh nut 12*. Assoon as the collar sections are spread apart sov asto. disengagethelugsl8.fr.om the wrench j holesithewcollar ll,v is freed-from the nut. andthe towing. connection. between the two. airplanes, ,A andB is -broken.Thesplit collar 8 iswconn'ected to theeyebolt Ill by flexibleconnectionzfl in order that it. moves. forwardswiththe member! upon.release or spreadingapart'of the .collarsections 14.- The connectionizllis preferably in the: form of aicord one end otwhich is anchored on attachedetothe pivot pinlfi and the. other-endof which isstiedsaround or.otherwise suitably secured tothe-shankl I of the eyeboltv Ill. The upperends of .the collarsections l4 are provided with a..pair-,cfoutwardlyextending ears 2|. These ears: anetpreferably welded. to theupperrendstof thecollar sections, and are so arranged or located that:they, are spacedasmall distance apartwhen the {collar sectionsare intheir-closed position.

The upper ends of the ears 2| are provided with upwardly and rearwardly,extended notches .22 whichzregister withone another when the collarsectionsare in their closed ornormal operating positionwherein the rearends thereof surround and-are interlocked with, the propeller hub nut bI The latchidevice 9 serves releasabl to. secure the, collar sectionsin-their closed position-and f coacts with the ears 2! on theupper-.ends-of the" collar sections. it is releasable; by the. pilot .of

theairplaneB while the latter isinflight-and beir1g.towed- -byv the towairplane A and-consistsof an upstanding vertically .elongated lever.type

'\ latch platelli, a bolt-24 and a release cable-.25., ThBEIOWEIDOI'HOIL of the plate 23 isadapted to fitbetweentheears 2! when thecollar sections I l-Hare intheir closed-position and has at the bottomthereof: a straight surface ZB- and a de- 7 pending. finger Z'l at. therear endof said. surface.

When'theilatch plate 23 is inits operative position whereinthe-:lowerportion thereof-fits between ears 2i the straight surface 26rests :on the upperaends .of-.the collar sections ld:and-th e-depending: finger. '21 is; in lapped relation with the rear; face.l-porti'ons :of saidv upper ends of the collar sections as showninFigure 4. The bolt 24 oft-the latch device 9 extends througha hcle'28in-thje latch plate -23. Such holeisdisposed above r; the .front-- end:oi. the straight surface 25 1 on %.the. b ttom of the lower portion ofthe latch plate.

and leads into the pilots compartment 12 notches 22 in the ears 2| andthe head and nut atthe ends of the shank fit against the outer faces ofthe ears and thus lock the ears together. When a rearward force isexerted on the upper end of the latch plate 23, the latch plate iscaused to swing in a clockwise direction as viewed in Figure 4 resultingin the bolt 24 becoming disconnected from the ears 2| thus releasing thelatch device 9 so that the collar sections M are free to swing apart. Inconnection with clockwise swinging or turning of the latch plate 23 thedepending finger 21 serves as the fulcrum or articulation point for theplate. The ears 2| and latch plate 23 are provided with registeringholes '29 through which a lock wire 30 may be inserted when the latchdevice is in its operative or latched position. When the latch device isreleased in response to clockwise turning of the latch plate 23 so as todisengage the bolt 24 from the notches 22 in the ears 2| the lock wire30 is sheared or severed. The release cable 25 leads rearwards from theupper end of the latch plate 23 into the pilots compartment b in thefuselage of the airplane B and serves as an instrumentality forpermitting the pilot of the airplane B to release the latch device 9 byswinging rearwards or in clockwise manner the latch plate 23. The frontend of the cable 25 is pivotally connected to the upper end of the latchplate 23 by a clevis 3|. The central portion of the cable extendsthrough and fits slidably in a guide tube 32 which is mounted on theupper portion of and extends lengthwise with respect to the cowl for thepropeller driving engine of the airplane B The rear end of the releasecable 25 is disposed within the pilots compartment b and embodies ahandle 33. In order to release the latch device 9, it is only necessaryfor the pilot of the airplane B to pull on the handle 33. When thehandle is pulled the release cable 2-5 is pulled rearwards and resultsin clockwise turning of the latch plate 23. In order to hold the releasecable 25 in its pulled back or retracted position and thus pre vent thelatch plate 23 from interfering with rotation of the propeller of theairplane B after release of the device 9 a coil spring 34 is provided.This spring is disposed in adepending position within the pilotscompartment b The upper end of the spring is suitably anchored withinthe upper portion of the pilots compartment and the lower end of thespring is provided with a hook 35 for attachment to an eye 36 on thehandle 33 at the rear end of the release cable 25. After the releasecable is pulled rearwards to effect release of the latch device 9 thespring 34 i distended and the hook '35 is inserted through the eye 36.Upon release of the spring after attachment of the hook to the eye thespring holds the cable 25 in its pulled back or retracted positionwherein the latch plate 23 is disposed rearwards of the arc of swing ofthe propeller for the airplane B.

When it is desired to tow the airplane B by the tow airplane A thetowing mechanism is connected or rendered operative by first swingingapart the collar sections 8. After the collar sections are swung orspread apart the hemispherical swivel variety connecting memberT-ispositioned within the front ends of the collar sections andthe-collar sections are shifted around the propeller hub nut b are swungtogether in order to bring the lugs I8 into interfitting relation withthe wrench holes b in the front end of the nut. As soon as the collarsections are swung together the collar is in connected relation with thepropeller hub nut and the connecting member 1 is disposed in the flangeformed socked in the front end of the collar and is free to swivel withrespect to the collar. After swinging together the two collar sectionsthe latch device 9 is rendered operative by inserting the lower portionof the latch plate 23 between the ears 2| and manipulating the plateinto a position wherein the straight surface 26 rests on the upper endsof the collar sections and ends of the bolt 24 fit within the rearwardlyand upwardly extended notches 22 in the upper ends of the ears 2|. Afterthe latch plate 23 is manipulated into place the lock wire 30 isinserted through the holes 29 and the ends thereof are twisted together.When the airplane B is being towed by the tow airplane A and it isdesired to release the airplane B the pilot for the latter airplanepulls on the handle 33 so as to retract the release cable 25. Retractionof the release cable causes the latch plate 23 to turn in a clockwisedirection as viewed in Figure 4 and results in disengagement of the bolt24- from the notches 22 in the ears 2|. As soon as the bolt 24 isdisengaged or removed from the notches the swivel variety connectingmember 1 cams or forces the collar sections 4 apart thereby effectingremoval of the lugs l8 from the wrench holes b in the propeller hub nutb and effecting release of the collar from the nut. Immediately uponrelease of the collar from the nut the airplane B is free with respectto the tow airplane A. As a result of the fact that the collar 8 isconnected to the swivel variety connecting member by the flexibleelement 20 the collar travels or moves with the member afterdisconnection thereof from the propeller hub nut 13 When the airplane Bis released from the airplane A the pilot for the airplane B connectsthe lower end of the spring 34 to the eye 36 on the handle 33 in orderto hold the release cable 25 in its pulled back or retracted positionwherein as previously pointed out the latch plate 23'is disposedrearwards of the pro peller of the 'airplane B. It is contemplated thatdirectly after attachment of the spring 36 to the handle 33 the pilotforthe airplane B will start the engine'in order to efiect propulsion ofthe airplane B as the result of drive of the propeller.

The herein described towing mechanism effectively and eiiicientlyfulfills itsintended purpose and may be released withfacility. Itconsists of but a small number of parts and hence may be produced at alow or reasonable cost. By reason of the fact that the towing mechanismincludes the releasable latch device 9, the mechanism may be released atthe will of the pilot for the'airplane v that is being towed.

The invention is not to be understood as restricted to the details setforth since these may be modified within the scope of the appendedclaims without departing from the spirit and scope of the invention.

Having thus described the invention what we claim as new and desire'tosecure by Letters Patent is:

l. A mechanism designed for use in flight towing by a tow aircraft anaircraft with a forwardly extending element, and comprising a tow cablehaving the front end thereof adapted for attachment to the tow aircraft;a split collar at the Thereafter the collar sections and their c'distal'ends-iprovided: withfreleasable means for securing them together;embodyingqon: one-section thereof. meansafor rinterfittingywith; the=element,.. and adapted: uponzrelease'of the spread apart anduenderinefiective the interfit releasable:'securingameans.to;have itsssectionstingrmeans, and jineans cohnectecl 'to'saidrrear end' of the towcable:and operative during :towing of the secondmentioned :aircraft and uponrelease of 1said releasable" securing .-:means automaticallyandsubstantialiy instantaneously :to spread apart the collar isections.

mechanism vdesigned LfOY. use in: flight tow-' ingcby'a tow airplaneatractor'typeaainplane hav- I ingz-in 'frontof its propeller acylindrical propeller l1ub:;.nutr:w-ith sideholes therein,;andcomprising.

a towszcableiahaving therfront end thereof adapted-c fonattachment .to.the .tow airplane a split.c0llar disposeda complementalsections having.r certain;-

opposed ends thereof pivotaily connected together intorderthat thesections :are 'free to-swing-to andfromzonelanother into and out ofa'normal operatingz-positionppriovided at-the distal endsi of thesections. with'rreleasable means-for securing the sections. ::in; theirz'operatingiposition, embodying inwardly extending lugs: onthesectionsfor: interfitting with the holes in the nut-whenrthe sections 1. are inzt'heirasaid operating position, and-adapted;

upon release of: the releasable securing '-means and "spreading apart-:of its sections to have .the lugswrwithdrawn, from :the holes in Ythei'nut, means: connected to :saidrear'iendnf. the tow eable and:

operative automatically; and ;substantially in stanta-neously duringtow-mg 1 of the tractor type airplane:;and upon release of-saidreleasable securing meansnito. spreadthe collar sectionsapar-t, and :aflexible connection betweenthe collar and said. rear. end of the-towcable wherebythe collar.-

is :caused to follow the rtow cab'le after -.discon--nectionwthereoffrom =the nut due. to spreading apart of-the collarsections.

3. -A .mechanism designed for -use in..flight towing by: a tow, airplanea tractor type airplane having a pilot's compartmenttherein andinaddition a cylindrical propeller hub nut. with. side holes therein-andcomprising a tow cable having, the front end-thereof adapted for.attachment tothe-tow aircraft, a split collar atthe ,rear end of l thetow 'cable, shaped-"to. fit over the -nut,..con--.

sisting of a -.pair -of "oppositely disposed complemental:semi-circularsections. having certain opposed: ends :thereof pivotally connectedtogether inv order that the --sections-. are free to swing .:to-.

and from one another into andoutofla normal operatingpositiongprovided'at the distal. ends of.

the sections with releasable means for securing the sections-in theiroperatingposition, embody-- ing inwardly extendingdugs on=the .centralpor-.-

tions ofthe sections .for .interfitting .-with..the

holes inthe nut when the sections .arein their. said operating position,andaadaptedupon release of the releasable securing means, and

spreading .apart ,ofjits. sections'to have the lugs 1 removed from theholes in the nut, means.

manipulable from'thepilots compartment ofthe tractor typeairplane-forreleasing said releasable securing means at will;-and means connected tothe rear end .OfIthGwtOW cable andoperativeduring-towingof said tractortype airpianeand uponxrelease of-saidreleasable rmeans-rtogspread-i;thecollar sectiomapar-t. s V 4.A-' mechanism designed-for-v use inflight;- towing by a tow aircraft anaircraft having at-e the frontendthereof a forwardly extending ele-- mentg. and comprising a tow cablehaving the: front end thereof adapted for attachment tothe tow aircraft,a-swivel variety rearwardlyflared connectingamember attached to the rearendof.

the tow cable,-, and a split lcollariny'the 'formzofa pair ofoppositelyydisposed complemented-sec.- tions, having. one-end thereofshaped-=to fit: around and interfit with the :elementjand lo -front endprovided with-:a wrearwardlyyfiared-c socket-for the connectingrmember,having cerq tain opposed .ends "of its sections-.:piv.otal1ycon nectedtogether, embodying releasable :means at i the distal ends of thesections for" securing thesections together, and adapted11130111."?1'9183/591 ofv prising -a towcable having the frontendthereof...

adapted for attachment to the tow 'saircraft; 7a;- swivelvarietyrearwardly flared connecting member attached to the rear endof the. towcable? and'a split collar in the form-ofta-pair ofzop-w.

positely disposed complemental semi-circular sections, having the rearend thereof shaped to; 1 fit around the element and provided iwithw'inwardly extending lugs .for interfitting with the side holes in theelement, and itsfront end'pro' vided'with a rearwardly-flaredrsooketfor. the 1 connecting member, having certain opposed .ends

of-its sections pivotally connected to'gethenembody'ing releasable meansat the'distal endsz-o'fr its sections for securing'the sectionstogether;

and'adapted upon release of the releasable secur-' ing means while thesecond mentioned aircraft isr being towed andin response to the wedgeaction of the connecting member on the socket .due'to forwardpull by thetow cable to have its sections'automatically spread apart intoa releasing position whereinthe lugs are disengagedfrom the holes in the elementand the connect-1 ing member isfree.

= front'end thereof adapted for'attachment'to the tow aircraft, a swivelvariety rearwardly flared connecting member attached'to the'rear ofthei:towcable, a split 'collar in the form of a -p'air of oppositely disposedcomplemental sections- "having the rear end thereof shaped'to fit-aroundand interfit" with the element and its front end provided with arearwardlyflared socket for the connecting member, havingcertain opposedends of its sections pivotally-connected together; em: f body'ingreleasable means at the distal ends -ofthe sections for securingthe'secti'ons'together,

and-"adapted upon release of the-"releasable 1 means while the secondmentio'ned aircraft" "is being towed-and'in response tothe wedge; actionofsaid r connecting m'e mber on -the socketcduel; i

to forward pull by the tow cable to have its sections automaticallyspread apart into an open position wherein they release said connectingmember and element, and means for tying the collar to said rear end ofthe tow cable so that it is caused to follow the cable and tow aircraftafter it is released or disconnected from said element.

7. A mechanism designed for use in flight towing by a tow aircraft anaircraft having at the front end thereof a forwardly extending element,and comprising a tow cable having the front end thereof adapted forattachment to the tow aircraft, a swivel variety rearwardly flaredconnecting member attached to the rear end of the tow cable, a splitcollar in the form of a pair of oppositely disposed complementalsections, having the rear end thereof shaped to fit around and interfitwith the element and its front end provided with a rearwardly flaredsocket for the connecting member, having certain opposed ends of itssections pivotally connected together, embodying releasable means at thedistal ends of the sections for securing the sections together, andadapted upon release of the releasable means while the second mentionedaircraft is being towed and in response to the wedge action of theconnecting member on the socket due to forward pull by the tow cable tohave its sections automatically spread apart into an open positionwherein they release said connecting member and element, tie means fortying the collar to said rear end of the tow cable in order that itfollows the cable and tow aircraft after it is released or disconnectedfrom the element, and means manipulable from said second mentionedaircraft for releasing said releasable securing means at will.

8. A mechanism designed for use in flight towing by a tow aircraft anaircraft having a pilots compartment therein and in addition a forwardlyextending element in front of the compartment, and comprising a towcable having the front end thereof adapted for attachment to the towaircraft a swivel variety rearwardly flared connecting member attachedto the rear end of the fitting with the element when the sections are intheir said operating position, and adapted when the sections are swungapart to have the interfitting means released and thereby effectdisconnection of the collar from the element and connecting member, anda latch device for releasably securing the collar sections in their saidoperating position, embodying a lever type latch plate shaped to fitbetween the ears, provided with parts for interlocking with the notchesin the ears, and adapted when moved in one direction to disconnect saidparts from the notches, a release cable for moving the plate in said onedirection having one end thereof connected to the plate and its otherend leading into the pilots compartment of the second mentioned airplaneand means for tying the collar to the rear end of the tow cable in orderthat it follows the tow cable upon disconnection thereof from theelement.

EDISON L. NOTESTEIN. ROBERT J. RUlVlPF.

REFERENGES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1.021481 Huff May 28, 19121,418,783 Fokker June 6, 1922 1,451,658 Hennekin Apr. 10, 1923 1,827,933Davis Oct. 20, 193 1,926,968 Causan Sept. 12, 1933

